Effect of health literacy and exercise interventions on glycated haemoglobin levels in Chinese patients with type 2 diabetes: a cluster-randomised controlled trial

Background

Patients with diabetes in China have low health literacy, which likely leads to poor glycaemic control and clinical outcomes. This study was designed to evaluate the effectiveness of health literacy-focused and exercise-focused interventions on glycated haemoglobin A_1c (HbA_1c) in the population.

Methods

In this cluster-randomised controlled trial conducted from Feb 20, 2015, through April 30, 2017, in Shanghai, China, 799 patients aged 18 years or older with type 2 diabetes from 40 clusters of general practitioner teams were randomised into three intervention arms or a control arm in blocks of eight clusters. The control group received usual care, the health literacy group was supplemented with individualised low literacy communications delivered by trained health-care providers using an interactive diabetes education toolkit, and the exercise group had usual diabetes care but was also asked to walk 3–5 times a week, 30–40 min per day in the first 6 months and 60–70 min per day in the following 6 months. Patients in the comprehensive intervention group were given both the literacy and exercise interventions. Assessments were conducted upon enrolment and after 3, 6, and 12 months of intervention. The study analysed improvement in HbA_1c at 12 months as a primary outcome. Ethics approval was obtained from the Medical Ethics Committee of Fudan University (IRB00002408 & FWA00002399, approval no 2013-06-0451). All participants provided written informed consent. This trial is registered with the International Standard Randomized Controlled Trial Number Register (no ISRCTN76130594).

Findings

Complete 12-month data were available for 761 (95%) patients, 192 in the control group, 188 in the health literacy group, 188 in the exercise group, and 193 in the comprehensive intervention group. Compared with the control group, the three intervention groups had decreased HbA_1c levels and were more likely to achieve goal HbA_1c levels (HbA1c ≤7·0%). After 3 months of intervention, the largest decrease was observed in the comprehensive intervention group, with an adjusted β of ?0·47% (95% CI ?0·73 to ?0·20), followed by the health literacy group (?0·35%, ?0·60 to ?0·10) and exercise group (?0·32%, ?0·57 to ?0·06). At the 6-month and 12-month assessments, the effect of the exercise intervention increased, with an adjusted β of ?0·73% (95% CI ?0·98 to ?0·47) and ?0·75% (?1·05 to ?0·45), respectively, while those for the health literacy group were ?0·35% (?0·61 to ?0·10) and ?0·65% (?0·94 to ?0·35), respectively. The decrease in HbA_1c was more pronounced in patients with higher literacy or numeracy levels at baseline.

Interpretation

Both health literacy-focused and exercise-focused interventions improved glycaemic control in Chinese patients with diabetes, particularly in patients with higher literacy or numeracy levels at baseline. Implementation of these approaches could be helpful at other public health clinics across China.

Funding

China Medical Board (CMB) Open Competition Project (No. 13-159) and the Social Science Fund of China National Ministry of Education (No. 14YJAZH092).